1. Field of the Invention
The present invention relates to a circuit and a method for driving a display device, more particularly to a circuit and a method for driving a display device which can prevent undesired bright lines or spots from appearing on a display screen when power supply is cut off
2. Description of the Related Art
A display device is driven with a voltage which is higher than a source voltage supplied from a battery or the like. To obtain such a drive voltage, a drive circuit of the display device comprises a booster circuit for boosting a source voltage from a battery or the like up to a plurality of predetermined high voltages. The drive circuit has its power source circuit and it outputs a plurality of different voltages because the display device needs different voltages to its scanning electrodes and signal electrodes for time-sharing addressing.
A booster circuit or a dividing circuit is used as such a power source circuit which outputs a plurality of different voltages. The booster circuit boosts a source voltage into a plurality of different voltages. The booster circuit boosts a voltage by switching connection of a plurality of capacitors so that charged voltages in the capacitors are added to each other. The dividing circuit divides a previously boosted voltage into a plurality of different voltages. The dividing circuit divides a boosted source voltage with a series circuit of resistors or capacitors.
A capacitor-based booster or dividing circuit is advantageous to reduce its power consumption.
Each of output lines of the power source circuit has a plurality of capacitors in order to output stable voltages.